Petroleum based products are some of the easiest to remove from water. The Black Berkey® Purification Elements have been tested to remove the following petroleum contaminants up to 99.9%:
However, please keep in mind that it is possible to overwhelm filtration elements. For example, removing a gallon of kerosene from a 1,000 gallon pool should not be problem (time consuming, but not a problem). Removing a gallon of kerosene from 2 gallons of water & kerosene mixed would probably overwhelm any gravity fed element.